JP2019038475A - Brake power control device and automatic steering system - Google Patents

Abstract

To provide a brake power control device and an automatic steering system transferrable to manual operation without disturbing behavior of a vehicle when finishing abnormality of automatic steering.SOLUTION: A brake power control device is the brake power control device for controlling a brake power distribution device of adding the yaw moment to a vehicle by controlling at least one of a brake force difference and a driving force difference in left-right wheels of the vehicle, and comprises an abnormality diagnosis part for detecting the occurrence of a steering control abnormal state of becoming impossible in a steering angle change operation of the vehicle when executing automatic steering of the vehicle and a brake power control part of adding the yaw moment to the vehicle so that the vehicle travels along a target course shape when the steering control abnormal state is caused.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle braking / driving force control device and an automatic steering system.

  For example, as disclosed in Japanese Patent Application Laid-Open No. 2002-175597, an external environment recognition device that recognizes the environment around the vehicle, such as the shape of a road ahead of the vehicle, is provided, and the vehicle is automatically operated based on the recognition result of the device. A traveling control system that performs driving is known.

JP 2002-175597 A

  In a vehicle capable of automatic driving, if a failure occurs in a device related to automatic driving due to, for example, a failure of an external environment recognition device or a cable disconnection, the control of automatic driving abnormally ends immediately. Until the driver of the vehicle recognizes the abnormal end of automatic driving by a warning sound or the like and starts manual driving, the vehicle is not steered, so the behavior of the vehicle may be disturbed during this period. is there.

  The present invention solves the above-described problems, and an object thereof is to provide a braking / driving force control device and an automatic steering system that can shift to manual operation without disturbing the behavior of the vehicle at the time of abnormal termination of automatic operation. And

  A braking / driving force control device according to an aspect of the present invention controls a braking / driving force distribution device that adds a yaw moment to the vehicle by controlling at least one of a braking force difference and a driving force difference between left and right wheels of the vehicle. A driving force control device, wherein the vehicle includes a steering assist device that controls a steering device that includes an actuator that changes a rudder angle and performs automatic steering that causes the vehicle to travel along a target course shape; The braking / driving force control device includes an abnormality diagnosis unit that detects occurrence of a steering control abnormality state in which the steering angle change operation of the vehicle based on the control of the steering assist device is impossible, and the steering control abnormality during the automatic steering. A braking / driving force control unit that applies a yaw moment to the vehicle so that the vehicle travels along the target course shape when a state occurs.

  An automatic steering system according to one aspect of the present invention includes a steering control device that controls a steering device including an actuator that changes a steering angle of a vehicle, and at least one of a braking force difference and a driving force difference between the left and right wheels of the vehicle. Calculating a target course shape from at least one of the external environment information and map information of the vehicle, and a braking / driving force control apparatus that controls a braking / driving force distribution apparatus that adds a yaw moment to the vehicle by controlling, and the target course A steering assist device that controls the steering control device based on a shape and performs an automatic steering for causing the vehicle to travel along the target course shape, wherein the braking / driving force control device includes: An abnormality diagnosing unit for detecting the occurrence of an abnormal steering control state in which the steering angle changing operation of the vehicle based on the control of the steering assist device is impossible; If the Oite the steering control abnormal state has occurred, and a braking-driving force control unit for adding a yaw moment to the vehicle so that the vehicle travels along the target trajectory shape.

  ADVANTAGE OF THE INVENTION According to this invention, the braking / driving force control apparatus and automatic steering system which can transfer to manual driving | operation without disturbing the behavior of a vehicle at the time of abnormal end of automatic driving | operation can be provided.

It is a block diagram which shows the structure of an automatic steering system. It is a flowchart which shows operation | movement of a steering control apparatus. It is a figure which shows the outline | summary of the calculation method of the 3rd steering instruction value by the instruction value calculating part at the time of network abnormal state generation | occurrence | production. It is a figure which shows the outline | summary of the calculation method of the 2nd steering instruction value by the instruction value calculating part at the time of steering instruction abnormal state generation | occurrence | production.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the drawings used for the following description, the scale of each component is made different in order to make each component recognizable on the drawing. It is not limited only to the quantity of the component described in (1), the shape of the component, the ratio of the size of the component, and the relative positional relationship of each component.

  An automatic steering system 100 according to the present embodiment shown in FIG. 1 is a device that is mounted on a vehicle and controls the operation of the steering device 1 provided in the vehicle. The steering device 1 is an electric power steering device that includes an electric actuator, for example, and changes the steering angle of the vehicle by the output of the electric actuator. The automatic steering system 100 executes the automatic steering in the automatic driving function and the driving support function of the vehicle by controlling the steering device 1.

  The automatic steering system 100 includes a steering assist device 10, a steering control device 20, and a braking / driving force control device 30. The vehicle also includes a steering device 1, a braking / driving force distribution device 2, a state quantity detection device 3, a notification unit 4, and a communication network 5.

  In the present embodiment, as an example, the steering assist device 10, the steering control device 20, and the braking / driving force control device 30 are connected to the communication network 5 and perform data communication with each other via the communication network 5.

  The braking / driving force distribution device 2 generates at least one of a braking force difference and a driving force difference between the left and right wheels of the vehicle. The operation of the braking / driving force distribution device 2 is controlled by a braking / driving force control device 30 described later. When the braking / driving force distribution device 2 generates a braking force difference or a driving force difference between the left and right wheels, a yaw moment is added to the vehicle. The braking / driving force distribution device 2 constitutes a skid prevention device, and since the configuration of the braking / driving force distribution device 2 is known, detailed description thereof is omitted.

  The state quantity detection device 3 includes a plurality of sensors that detect the state quantity of the vehicle. The vehicle state quantity includes at least a vehicle speed V that is the speed of the vehicle, an acceleration α in the longitudinal direction of the vehicle, a yaw rate Yawr that is an angular velocity in the yaw direction of the vehicle, and a steering angle of the steering device 1. That is, the state quantity detection device 3 includes at least a vehicle speed sensor, an acceleration sensor, a yaw rate sensor, and a steering angle sensor. Since these sensors are well-known techniques, detailed description is omitted. Note that since the acceleration α in the longitudinal direction of the vehicle can be calculated from the vehicle speed V, the state quantity detection device 3 may not include an acceleration sensor.

  Part or all of the state quantity detection device 3 may be included in the automatic steering system 100. In the present embodiment, as an example, the yaw rate sensor 3 a included in the braking / driving force control device 30 constitutes a part of the state quantity detection device 3.

  Information on the state quantity output from the state quantity detection device 3 is input to a steering assist device 10, a steering control device 20, and a braking / driving force control device 30 described later. Communication between the state quantity detection device 3, the steering assist device 10, the steering control device 20, and the braking / driving force control device 30 is performed via the communication network 5 provided in the vehicle. Communication between the state quantity detection device 3 and the steering assist device 10, the steering control device 20, and the braking / driving force control device 30 may be performed using a dedicated communication cable without using the communication network 5. .

  The notification unit 4 includes, for example, a display device that displays images and characters, a light emitting device that emits light, a speaker that emits sound, a vibrator that emits vibration, or a combination thereof, and the like from the automatic steering system 100 to the driver. Output information.

  The steering assist device 10 includes a map information recognition device 11, an external recognition device 12, a first steering instruction value calculation unit 13, and a first abnormality diagnosis unit 15.

  The map information recognition device 11 stores map information and a positioning device 11a that detects the current position (latitude, longitude) of the vehicle using at least one of a satellite positioning system (GNSS), an inertial navigation device, and road-to-vehicle communication. A map information storage unit 11b. The map information includes information indicating the shape of the road such as the curvature of the road, the gradient of the longitudinal section, and the state of intersection with another road.

  The map information recognition device 11 recognizes the shape of the traveling road ahead of the vehicle based on the current position of the vehicle detected by the positioning device 11a and the map information stored in the map information storage unit 11b.

  The external environment recognition device 12 recognizes the shape of the traveling road ahead of the vehicle and the position of an object existing on and around the traveling road based on information from a sensor that recognizes the external environment of the vehicle. Is output as external environment information.

  The external environment recognition device 12 includes, for example, a stereo camera that keeps the front of the vehicle within the field of view, and recognizes the environment ahead of the vehicle by performing known image processing or the like on the image captured by the stereo camera. Specifically, the external environment recognition device 12 recognizes linear markings provided on the road surface along the traveling road of the vehicle, other vehicles on the road surface, pedestrians, and the like. A linear marking is a linear or dashed road marking formed on the road surface along the left and right boundaries of the vehicle lane to indicate the vehicle lane. Since an apparatus for recognizing an environment in front of a vehicle using a stereo camera is known, a detailed description of the configuration is omitted. Note that the external environment recognition device 12 may use a radar or a laser radar in addition to the camera.

  The first steering instruction value calculation unit 13 includes a computer in which a CPU, a ROM, a RAM, an input / output device, and the like are connected to a bus. The first steering instruction value calculation unit 13 has a shape of a traveling path on which the vehicle travels based on at least one of the map information output from the map information recognition device 11 and the external environment information recognized by the external environment recognition device 12. A certain target course shape is calculated.

  Further, the first steering instruction value calculator 13 is a state quantity (yaw angle deviation, lateral position deviation, etc.) with respect to a target course shape recognized by the map information recognition device 11 or the external environment recognition device 12 during automatic steering of the vehicle. Then, based on the state quantity detected by the state quantity detection device 3, a first steering instruction value, which is control data output to the steering device 1 to drive the vehicle along the target course shape, is calculated. The first steering instruction value is information that becomes a target value of steering that the steering device 1 should execute so that the vehicle travels along the target course shape. In the present embodiment, the first steering instruction value is, for example, a target steering angle value that the steering device 1 should change. The first steering instruction value may be a value of a steering torque that should be generated by the electric actuator provided in the steering device 1.

  The first steering instruction value output from the first steering instruction value calculation unit 13 is input to the steering control device 20 described later.

  In addition, the first steering instruction value calculation unit 13 has a future course shape that is a target course shape that causes the vehicle to travel from the present to A seconds after a predetermined time, based on at least one of the map information and the external environment information. Calculate information. The predetermined time A is, for example, about 5 seconds. The first steering instruction value calculation unit 13 outputs information on the future course shape to the steering control device 20 and the braking / driving force control device 30 described later.

  The calculation of the future course shape may be performed by the steering control device 20 and the braking / driving force control device 30 described later. In this case, the steering assist device 10 outputs map information and external environment information, which are information necessary for calculating the future course shape, to both the steering control device 20 and the braking / driving force control device 30.

  The first abnormality diagnosis unit 15 detects the occurrence of a steering control abnormality state in which the steering angle change operation of the vehicle by the steering control device 20 based on the control of the steering assist device 10 becomes impossible during automatic steering. The steering control abnormal state is a state in which at least one of the steering device 1 and the steering control device 20 is out of order.

  The method by which the first abnormality diagnosis unit 15 detects the occurrence of the steering control abnormality state is not particularly limited. In the present embodiment, as an example, the first abnormality diagnosis unit 15 outputs the yaw rate based on the first steering instruction value when the steering control device 20 outputs information indicating that a failure has occurred in its own operation. Is not detected by the state quantity detection device 3, it is determined that a steering control abnormal state has occurred.

  The first steering instruction value calculation unit 13 of the present embodiment calculates the yaw rate instruction value information when the first abnormality diagnosis unit 15 detects the occurrence of an abnormal steering control state, and the braking / driving force control device 30. Output to. The yaw rate instruction value is a yaw rate value that the braking / driving force distribution device 2 should generate in the vehicle in order to cause the vehicle to travel along the target course shape without changing the steering angle. The first steering instruction value calculation unit 13 calculates the yaw rate instruction value based on the state quantity (yaw angle deviation, lateral position deviation, etc.) with respect to the target course shape and the state quantity detected by the state quantity detection device 3.

  The steering control device 20 is composed of a computer having a CPU, ROM, RAM, input / output device and the like connected to a bus. The steering control device 20 includes a storage unit 22, a second abnormality diagnosis unit 23, an instruction value calculation unit 24, and a switching unit 25. Further, the steering control device 20 is electrically connected to the steering device 1. These components included in the steering control device 20 may be implemented as separate hardware that executes individual functions, or software such that individual functions are achieved by the CPU executing a predetermined program. May be implemented.

  The storage unit 22 stores a future course shape, which is a target course shape in which the vehicle travels within a predetermined time A seconds after the present time, and a current state quantity. The current state quantity is the latest state quantity data output from the state quantity detection device 3. The vehicle state quantities stored in the storage unit 22 include at least the vehicle speed V, which is the speed of the vehicle, the acceleration α in the longitudinal direction of the vehicle, the yaw rate Yawr, which is the angular velocity in the yaw direction of the vehicle, and the steering angle of the steering device 1. included.

  The future course shape and the state quantity stored in the storage unit 22 are constantly updated at a predetermined cycle. Note that the future cycle shape update cycle and the state quantity update cycle may be the same or different.

  The second abnormality diagnosing unit 23 detects the occurrence of a communication network abnormal state in which the communication network 5 has failed during automatic steering, and detects a steering instruction abnormal state in which the steering assist device 10 has failed during automatic steering. Occurrence detection.

  The network abnormal state is a state in which data communication via the communication network 5 is impossible. The steering instruction abnormal state is a state in which information indicating that a failure has occurred in its own operation is being output from the steering assist device 10 or a state in which data communication with the steering assist device 10 is not possible. In the steering instruction abnormal state, the steering device 1, the state quantity detection device 3, the communication network 5, the steering control device 20, and the braking / driving force control device 30 are operating normally.

  That is, in a network abnormal state, the steering control device 20 receives the first steering instruction value and the future course shape information output from the steering assist device 10 and the state output from the state quantity detection device 3. The amount of information cannot be received. Further, in the case where the steering instruction is abnormal, the steering control device 20 cannot receive the first steering instruction value and the future course shape information output from the steering assist device 10, but the state quantity detection device It is possible to receive information on the state quantity output from 3.

  The instruction value calculation unit 24 stores the future course stored in the storage unit 22 when the second abnormality diagnosis unit 23 detects that the network abnormality state or the steering instruction abnormality state is detected during automatic steering of the vehicle. An instruction value to be output to the steering device 1 to drive the vehicle along the shape is calculated.

  Specifically, the instruction value calculation unit 24 sets the state quantity input from the state quantity detection device 3 and the future course shape stored in the storage unit 22 when the steering instruction is abnormal during automatic steering. Based on this, a second steering instruction value to be output to the steering device 1 in order to drive the vehicle along the future course shape is calculated.

  In addition, the instruction value calculation unit 24, in the case of a network abnormal state at the time of automatic steering, based on the latest state quantity and the future route shape stored in the storage unit 22 along the future route shape. A third steering instruction value that is output to the steering device 1 to drive the vehicle is calculated.

  The switching unit 25 controls the steering device 1 based on the first steering instruction value output from the steering assist device 10 when the automatic steering is not in the network abnormal state or the steering instruction abnormal state, and the steering instruction abnormality is detected. When it is in the state, the steering device 1 is controlled based on the second steering instruction value output from the instruction value calculation unit 24, and when it is in the network abnormal state, the second value output from the instruction value calculation unit 24. 3. Steering device 1 is controlled based on the steering instruction value.

  That is, when the operations of the steering assist device 10, the state quantity detection device 3, and the communication network 5 are normal, the automatic steering system 100 automatically detects the vehicle based on the first steering instruction value calculated by the steering assist device 10. Steer.

  Further, the automatic steering system 100 is in a case where a failure occurs in the steering assist device 10 during automatic steering of the vehicle, and the operation of the communication network 5 and the state quantity detection device 3 is in a normal steering instruction abnormal state. The vehicle is automatically steered based on the second steering instruction value calculated by the instruction value calculation unit 24 provided in the steering control device 20.

  Further, the automatic steering system 100 is configured such that the third steering instruction value calculated by the instruction value calculation unit 24 included in the steering control device 20 is in a network abnormal state in which a failure occurs in the communication network 5 during automatic steering of the vehicle. Based on this, the vehicle is automatically steered.

  Next, operations related to automatic steering of the steering control device 20 will be described with reference to a flowchart shown in FIG. The steering control device 20 executes the process shown in FIG. 2 when the vehicle is traveling.

  First, in step S100, the steering control device 20 stands by until an instruction operation for starting automatic steering is input by the driver of the vehicle. When the steering control device 20 determines that an instruction operation for starting automatic steering by the driver has been input, the steering control device 20 starts processing from step S110.

  In the following description, it is assumed that time is represented by a variable t and the current time is t = 0. The vehicle speed, which is the speed of the vehicle, is a variable V (t) that changes with time, and the acceleration in the longitudinal direction of the vehicle is a variable α (t) that changes with time. Let the yaw rate be a variable Yawr (t) that changes over time. Further, a lateral position deviation, which is a deviation amount in the vehicle width direction of the vehicle position with respect to the target route shape, is defined as a variable ErrX (t) that changes with time, and is a deviation amount in the yaw direction of the vehicle direction with respect to the target route shape. The yaw angle deviation is defined as a variable ErrYaw (t) that changes over time.

  In step S110, the steering control device 20 starts storing the future course shape and the current state quantity of the vehicle and updating the stored contents by the storage unit 22. As described above, the future course shape is a target course shape for causing the vehicle to travel from the present to A seconds after a predetermined time. The state quantity includes a vehicle speed V (0) that is the speed of the vehicle, an acceleration α (0) in the longitudinal direction of the vehicle, a yaw rate Yawr (0) that is an angular velocity in the yaw direction of the vehicle, and the steering angle of the steering device 1. At least included.

  In the present embodiment, as an example, the storage unit 22 includes a vehicle speed V (0) that is the speed of the vehicle, an acceleration α (0) in the front-rear direction of the vehicle, a yaw rate Yawr (0) that is an angular speed in the yaw direction of the vehicle, The lateral position deviation ErrX (0) and the yaw angle deviation ErrYaw (0) representing the current vehicle deviation with respect to the target course shape are stored. The position deviation ErrX (0) and the yaw angle deviation ErrYaw (0) are values calculated by the steering assist device 10 and are input to the steering control device 20. Since the information stored in the storage unit 22 always changes when the vehicle is running, it is constantly updated when the vehicle is in a normal state.

  Next, in step S <b> 120, the steering control device 20 starts automatic steering for controlling the steering device 1 based on the first steering instruction value calculated by the first steering instruction value calculation unit 13 included in the steering assist device 10. Since the control of automatic steering by the steering assist device 10 is the same as that of a known technique, a detailed description thereof is omitted. Schematically, the first steering instruction value calculation unit 13 of the steering assist device 10 determines a target course shape based on the latest recognition results by the map information recognition device 11 and the external recognition device 12, and the map information recognition device 11. The first steering instruction value is obtained by feedforward control and feedback control based on information such as the yaw angle deviation and lateral position deviation of the host vehicle with respect to the target course shape recognized by the external recognition device 12 and the state quantity of the vehicle. calculate.

  After starting the automatic steering based on the first steering instruction value, if the steering control device 20 is in a normal state, the steering control device 20 continues the automatic steering until an instruction operation for ending the automatic steering by the driver is input (step S150). YES)

  If the abnormality detection unit 23 detects that the network is abnormal during execution of automatic steering (YES in step S130), the steering control device 20 proceeds to step S200.

  In step S200, the steering control device 20 notifies the driver via the notification unit 4 that a failure has occurred and automatic steering is to be terminated after A seconds. In step S210, the steering control device 20 continues the automatic steering for controlling the steering device 1 based on the third steering instruction value calculated by the instruction value calculation unit 24 for A seconds from the detection of the occurrence of the network abnormal state.

  An outline of a method for calculating the third steering instruction value by the instruction value calculation unit 24 is shown in FIG. In the following, it is assumed that a network abnormal state has occurred at time t = T1, and the elapsed time from time T1 is δT.

  Since the network abnormal state is a state in which communication between both the steering instruction device 10 and the state quantity detection device 3 and the steering control device 20 is interrupted, the network abnormal state is stored in the storage unit 22 after the occurrence of the network abnormal state. The future course shape, the lateral position deviation ErrX (t), the yaw angle deviation ErrYaw (t), and the vehicle state quantity are not updated. Therefore, after the occurrence of the network abnormal state, the storage unit 22 stores the future course shape at the time T1, the lateral position deviation ErrX (T1) and the yaw angle deviation ErrYaw (T1) at the time T1, and the state quantities at the time T1. It is remembered. The state quantities at time T1 are vehicle speed V (T1), acceleration α (T1), and yaw rate Yawr (0). A value surrounded by a broken-line rectangular frame in FIG. 3 is a value stored in the storage unit 22.

  At the time of occurrence of the network abnormal state, the instruction value calculation unit 24 stores the future course shape and vehicle state quantity stored in the storage unit 22 at the time of occurrence of the network abnormal state (t = T1), and the progress from the occurrence of the network abnormal state. Based on the time δt, the curvature Ce (0) of the target course is estimated. Specifically, the instruction value calculation unit 24 calculates the current vehicle speed Ve (0) of the vehicle based on the vehicle speed V (T1) and acceleration α (T1) at the time of occurrence of the network abnormal state and the elapsed time δt. presume. Then, the travel distance is calculated from the integrated value of the estimated vehicle speed Ve (0) for the past δt seconds from the present time, the current position of the vehicle on the stored future course shape is estimated, and the target position is determined from this current position and the future course shape. The path curvature Ce (0) is estimated.

  Then, the instruction value calculation unit 24 changes the yaw angle of the vehicle to the yaw angle along the target route based on the current estimated vehicle speed Ve (0) and the estimated curvature Ce (0) of the target route in the target yaw rate calculation unit. The target yaw rate required for the calculation is calculated. The target yaw rate is a value calculated from the current estimated vehicle speed Ve (0) and the estimated curvature Ce (0) of the target course.

  In addition, the instruction value calculation unit 24, when the network abnormal state occurs (t = T1), the lateral position deviation ErrX (T1), which is a deviation in the vehicle width direction of the current vehicle with respect to the target route, or the current vehicle with respect to the target route. If the yaw angle deviation ErrYaw (T1), which is an angle deviation in the yaw direction, exceeds a predetermined value, the corrected yaw rate calculation unit calculates the corrected yaw rate necessary for returning the vehicle to the future course in the horizontal position. Calculation is performed using the deviation ErrX (T1) and the yaw angle deviation ErrYaw (T1). That is, the corrected yaw rate is for compensating for a deviation from the target course of the vehicle due to, for example, a disturbance such as a cant on the road surface or a crosswind.

  Then, the instruction value calculation unit 24 adds the target yaw rate and the corrected yaw rate, and based on this result, the first target rudder angle calculation unit calculates the first target rudder angle. The calculation of the first target rudder angle includes a rudder angle correction gain for correcting a deviation between a preset vehicle motion characteristic and an actual vehicle motion characteristic.

  Then, the instruction value calculation unit 24 outputs the first target steering angle as the third steering instruction value. That is, the third steering instruction value used for automatic steering when a network abnormal state occurs is used for feedforward control of the steering device 1 based on information on the future course shape and the vehicle state quantity stored in the storage unit 22. Only the component of the first target rudder angle is included. The third steering instruction value does not include a component for feedback control of the steering device 1.

  Since the information on the future course shape stored in the storage unit 22 at the time of occurrence of the network abnormal state is within a predetermined time (A seconds), the instruction value calculation unit is A seconds after the occurrence of the network abnormal state. 24 finishes the calculation of the third steering instruction value.

  Returning to the flowchart of FIG. 2, the steering control device 20 proceeds to step S300 when the abnormality detection unit 23 detects that the steering instruction is abnormal during execution of automatic steering (YES in step S140). To do.

  In step S300, the steering control device 20 notifies the driver via the notification unit 4 that a failure has occurred and automatic steering is to be terminated after A seconds. In step S310, the steering control device 20 continues the automatic steering for controlling the steering device 1 based on the second steering instruction value calculated by the instruction value calculation unit 24 for A seconds from the detection of the occurrence of the network abnormal state.

  An outline of a method for calculating the second steering instruction value by the instruction value calculation unit 24 is shown in FIG. In the following, it is assumed that the steering instruction abnormal state has occurred at time t = T1, and the elapsed time from time T1 is δT.

  Since the steering instruction abnormal state is a state in which communication between the steering assist device 10 and the steering control device 20 is interrupted, the future course shape stored in the storage unit 22 after the occurrence of the steering instruction abnormal state, The values of the lateral position deviation ErrX (t) and the yaw angle deviation ErrYaw (t) are not updated. Therefore, after the occurrence of the steering instruction abnormal state, the storage unit 22 stores the future course shape at time T1, the lateral position deviation ErrX (T1), and the yaw angle deviation ErrYaw (T1) at time T1. A value surrounded by a broken-line rectangular frame in FIG. 4 is a value stored in the storage unit 22.

  When the steering instruction abnormal state occurs, the instruction value calculation unit 24 calculates the future course shape stored in the storage unit 22 when the steering instruction abnormal state occurs (t = T1) and the elapsed time δt from the occurrence of the steering instruction abnormal state. And the curvature Ce (0) of the target course is estimated based on the current vehicle speed V (0). Specifically, the instruction value calculation unit 24 calculates the travel distance from the integrated value of the vehicle speed for the past δt seconds from the present, estimates the current position of the vehicle on the stored future course shape, The curvature Ce (0) of the target course is estimated from the future course shape.

  Then, the instruction value calculation unit 24 causes the target yaw rate calculation unit to change the yaw angle of the vehicle to the yaw angle along the target route based on the current vehicle speed V (0) and the estimated curvature Ce (0) of the target route. The target yaw rate necessary for this is calculated. The target yaw rate is a value calculated from the current vehicle speed V (0) and the estimated curvature Ce (0) of the target course.

  In addition, the instruction value calculation unit 24, when the steering instruction abnormal state occurs (t = T1), the lateral position deviation ErrX (T1) that is a deviation in the vehicle width direction of the current vehicle with respect to the target route and the current vehicle with respect to the target route When the yaw angle deviation ErrYaw (T1), which is the angle deviation in the yaw direction, exceeds a predetermined value, the corrected yaw rate calculation unit calculates the corrected yaw rate necessary for returning the vehicle to the future course. The position deviation ErrX (T1) and the yaw angle deviation ErrYaw (T1) are used for calculation. That is, the corrected yaw rate is for compensating for a deviation from the target course of the vehicle due to, for example, a disturbance such as a cant on the road surface or a crosswind.

  Then, the instruction value calculation unit 24 adds the target yaw rate and the corrected yaw rate, and based on this result, the first target rudder angle calculation unit calculates the first target rudder angle. The calculation of the first target rudder angle includes a rudder angle correction gain for correcting a deviation between a preset vehicle motion characteristic and an actual vehicle motion characteristic.

  Further, the instruction value calculation unit 24 uses the yaw angle of the vehicle in the second target rudder angle calculation unit based on the value obtained by adding the target yaw rate and the corrected yaw rate and the yaw rate Yawr (0) that is the current state quantity of the vehicle. A second target rudder angle is calculated for feedback control so that the yaw angle along the target path becomes a yaw angle.

  The command value calculation unit 24 outputs a value obtained by adding the first target steering angle and the second target steering angle as a second steering command value. That is, the second steering instruction value used for automatic steering when the steering instruction abnormal state occurs performs feedforward control of the steering device 1 based on the future course shape stored in the storage unit 22 and the current vehicle speed V (0). And a second target rudder angle component for feedback control of the steering device 1 based on the current yaw rate Yawr (0) value of the vehicle.

  Since the information on the future course shape stored in the storage unit 22 when the steering instruction abnormal state occurs is within a predetermined time (A seconds), the instruction value is A seconds after the occurrence of the steering instruction abnormal state. The calculation unit 24 ends the calculation of the second steering instruction value.

  As described above, the steering control device 20 according to the present embodiment, during automatic steering, determines the future course shape according to the shape of the road on which the vehicle travels from the present to the future after a predetermined time, and the vehicle speed. Or the like is stored in the storage unit 22.

  When a steering instruction abnormal state occurs in which communication between the steering support device 10 including the map information recognition device 11 and the external recognition device 12 and the steering control device 20 that controls the steering device 1 is interrupted, steering is performed. The control device 20 controls the steering device 1 based on the stored future course shape and vehicle speed and yaw rate information detected in real time by the state quantity detection device 3, and continues automatic steering only for a predetermined period. In this case, since the estimation of the position of the vehicle and the feedback control of the steering angle can be executed in accordance with the change in the state quantity of the vehicle, the automatic steering system 100 performs a predetermined operation along the stored future course shape. The vehicle can be accurately driven only during the period.

  In addition, the steering control device 20 according to the present embodiment stores the memory even when a communication network abnormal state occurs in which communication between both the steering assist device 10 and the state quantity detection device 3 and the steering control device 20 is interrupted. The steering device 1 can be controlled based on the latest future course shape and state quantity, and the automatic steering can be continued so that the vehicle travels along the future course shape for a predetermined period.

  Therefore, according to the automatic steering system 100 of the present embodiment, after a failure occurs in the communication network or after a failure occurs in the steering assist device 10, the vehicle is allowed to travel along the future course shape during a predetermined period. Automatic steering can be continued. According to the automatic steering system 100 of the present embodiment, the automatic steering is abnormally terminated because the automatic steering can be shifted to the manual driving by the driver during the execution period of the automatic steering along the future course shape after the occurrence of the failure. In this case, it is possible to prevent the disturbance of the behavior of the vehicle.

  The braking / driving force control device 30 is composed of a computer in which a CPU, a ROM, a RAM, an input / output device and the like are connected to a bus. The braking / driving force control device 30 includes a yaw rate sensor 3a, a storage unit 32, a third abnormality diagnosis unit 33, and a braking / driving force control unit 34. Further, the braking / driving force control device 30 is electrically connected to the braking / driving force distribution device 2. As described above, in the present embodiment, the yaw rate sensor 3 a constitutes a part of the state quantity detection device 3.

  These configurations of the braking / driving force control device 30 may be implemented as separate hardware that executes individual functions, or the individual functions are achieved by the CPU executing a predetermined program. May be implemented in software.

  The storage unit 32 stores a future course shape, which is a target course shape in which the vehicle travels within a predetermined time A seconds after the present time, and a current state quantity. The vehicle state quantity stored in the storage unit 32 includes at least a vehicle speed V that is the speed of the vehicle, an acceleration α in the longitudinal direction of the vehicle, and a yaw rate Yawr that is an angular speed in the yaw direction of the vehicle.

  The future course shape and the state quantity stored in the storage unit 32 are constantly updated at a predetermined cycle. Note that the future cycle shape update cycle and the state quantity update cycle may be the same or different.

  The third abnormality diagnosis unit 33 is a communication failure that is at least one of a state in which a failure has occurred in the operation of the steering assist device 10 and a state in which a failure has occurred in the operation of the communication network 5 during automatic steering. Detect the occurrence of a condition.

  The communication failure state is a state where information indicating that a failure has occurred in its own operation is output from the steering assist device 10 or a state where data communication with the steering assist device 10 is not possible.

  Even when the operation of the communication network 5 is faulty, the braking / driving force control device 30 is detected by at least the yaw rate sensor 3a among the state quantities detected by the state quantity detection device 3. Information on the yaw rate Yawr can be acquired.

  In addition, the third abnormality diagnosis unit 33 detects the occurrence of a steering control abnormality state in which the steering angle changing operation of the vehicle by the steering control device 20 based on the control of the steering assist device 10 becomes impossible during automatic steering. As described above, the steering control abnormal state is a state in which at least one of the steering device 1 and the steering control device 20 is out of order.

  The third abnormality diagnosis unit 33 of the present embodiment receives information indicating that a steering control abnormal state has occurred from the steering assist device 10 or the steering control device 20 when the communication failure state has not occurred. In this case, it is determined that a steering control abnormal state has occurred.

  Further, when a communication failure state has occurred, the third abnormality diagnosis unit 33 uses an estimated yaw rate calculated based on the future course shape and the state quantity stored in the storage unit 32, and the yaw rate sensor 3a. When the absolute value of the difference from the detected actual yaw rate of the vehicle is greater than or equal to a predetermined threshold value, it is determined that a steering control abnormal state has occurred.

  More specifically, when a communication failure state occurs, the third abnormality diagnosis unit 33 determines the future course shape and vehicle state quantity stored in the storage unit 32 when the communication failure state occurs (t = T1), and the communication failure. The curvature Ce (0) of the target course is estimated based on the elapsed time δt from the occurrence of the state. Specifically, the third abnormality diagnosis unit 33 determines the current vehicle speed Ve (0) of the vehicle based on the vehicle speed V (T1) and acceleration α (T1) at the time of occurrence of the communication failure state and the elapsed time δt. Is estimated. In estimating the vehicle speed Ve (0), it is assumed that the acceleration of the vehicle is constant at α (T1). Then, the travel distance is calculated from the integrated value of the estimated vehicle speed Ve (0) for the past δt seconds from the present time, the current position of the vehicle on the stored future course shape is estimated, and the target position is determined from this current position and the future course shape. The path curvature Ce (0) is estimated.

  Next, the third abnormality diagnosis unit 33 calculates a yaw rate generated when the vehicle travels at the estimated vehicle speed Ve (0) and the estimated curvature Ce (0), and this value is calculated as an estimated yaw rate Yawre (0). To do.

  The third abnormality diagnosis unit 33 has a steering control abnormality state when the absolute value of the difference between the estimated yaw rate Yawre (0) and the actual yaw rate Yawr (0) is equal to or greater than a predetermined threshold value. Is determined.

  As described above, since the future course shape is in a relatively short period of about 5 seconds, when the steering device 1 is controlled by the steering control device 20, the estimated yaw rate Yawre (0) and the actual yaw rate Yawr The difference from (0) is not so large. Therefore, the case where the difference between the estimated yaw rate Yawre (0) and the actual yaw rate Yawr (0) is equal to or greater than a predetermined threshold is a case where steering for causing the vehicle to travel along the future course shape is not performed. It can be said that an abnormal state of steering control has occurred.

  When the vehicle is automatically steered, the braking / driving force control unit 34 has been detected by the third abnormality diagnosis unit 33 to be in a steering control abnormal state, and no communication failure state has occurred. When information on the yaw rate instruction value is received, a yaw moment is generated in the braking / driving force distribution device 2, and the braking / driving force distribution device 2 is controlled so that the yaw rate of the vehicle becomes the yaw rate instruction value.

  The braking / driving force control unit 34 detects that the steering abnormality abnormality state is detected by the third abnormality diagnosis unit 33 during automatic steering of the vehicle and a communication failure state occurs. A yaw moment is generated in the braking / driving force distribution device 2 so that the vehicle travels along the future course shape stored in the storage unit 32. In this case, the braking / driving force control unit 34 travels the vehicle along the future course shape based on the actual yaw rate detected by the yaw rate sensor 3a, the latest state quantity stored in the storage unit 32, and the future course shape. Therefore, the command yaw moment, which is information on the yaw moment to be generated by the braking / driving force distribution device 2, is calculated.

  In calculating the command yaw moment, first, the braking / driving force control unit 34 determines the future course shape and vehicle state quantity stored in the storage unit 32 when the communication failure state occurs (t = T1), and the occurrence of the network abnormal state. The estimated vehicle speed Ve (0) and the estimated curvature Ce (0) of the target route are calculated on the basis of the elapsed time δt. The calculation method of the estimated vehicle speed Ve (0) and the estimated curvature Ce (0) of the target route is as described above.

  The braking / driving force control unit 34 is necessary to change the yaw angle of the vehicle to the yaw angle along the target path based on the current estimated vehicle speed Ve (0) and the estimated curvature Ce (0) of the target path. Calculate the target yaw rate.

  The braking / driving force control unit 34 also determines the lateral position deviation ErrX (T1), which is a deviation in the vehicle width direction of the current vehicle with respect to the target route when the communication failure occurs (t = T1), and the current vehicle with respect to the target route. When the yaw angle deviation ErrYaw (T1), which is the angle deviation in the yaw direction, exceeds a predetermined value, a corrected yaw rate necessary for returning the vehicle to the future course is calculated.

  Then, the braking / driving force control unit 34 adds the target yaw rate and the corrected yaw rate, and calculates an instruction yaw moment based on the result. In addition to the values of the target yaw rate and the corrected yaw rate, the actual yaw rate value detected by the yaw rate sensor 3a, the preset vehicle mass information, and the position of each wheel with respect to the center of gravity of the vehicle Information is used. The actual yaw rate value is used for feedback control of the yaw rate of the vehicle.

  When the braking / driving force distribution device 2 gives the vehicle a yaw moment based on the value of the command yaw moment, the traveling direction of the vehicle changes so as to travel along the future course shape. Since the information on the future course shape stored in the storage unit 32 at the time of occurrence of the communication failure state is within a predetermined time (A second), the calculation of the command yaw moment by the braking / driving force control unit 34 is as follows: Continue for A second.

  As described above, in the automatic steering system 100 of the present embodiment, a failure has occurred in the steering device 1 or the steering control device 20 during the automatic steering of the vehicle. When the operation of the steering assist device 10 is normal, the control of changing the traveling direction of the vehicle by the braking / driving force control device 30 and the braking / driving force distribution device 2 based on information calculated by the steering assist device 10 is performed in a predetermined manner. Continue for time (A seconds).

  In addition, the automatic steering system 100 is configured to control the braking / driving force control device when a communication failure state occurs during the automatic steering of the vehicle and the steering assist device 10 cannot control the braking / driving force control device 30. 30 determines independently whether the steering apparatus 1 or the steering control apparatus 20 has trouble. The automatic steering system 100 controls the automatic steering system 100 based on information stored in the driving force control device 30 when a communication failure state has occurred and a failure has occurred in the steering device 1 or the steering control device 20. The change control of the traveling direction of the vehicle by the driving force control device 30 and the braking / driving force distribution device 2 is continued for a predetermined time (A second).

  Therefore, according to the automatic steering system 100 including the braking / driving force control unit 34 of the present embodiment, the vehicle is kept in a future course shape for a predetermined period even after a failure occurs in the steering device 1 or the steering control device 20. Can be run. Then, according to the automatic steering system 100 of the present embodiment, the automatic steering can be shifted to the manual driving by the driver during the execution period of the automatic traveling along the future course shape after the occurrence of the failure. It is possible to prevent disturbance of the behavior of the vehicle when it ends abnormally.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. Devices and automatic steering systems are also within the scope of the present invention.

1 Steering device,
2 braking / driving force distribution device,
3 state quantity detection device,
3a Yaw rate sensor,
4 Notification Department,
5 communication network,
10 steering assist device,
11 Map information recognition device,
11a coronation device,
11b Map information storage unit,
12 External environment recognition device,
13 1st steering instruction value calculation part,
15 First abnormality diagnosis section,
20 steering control device,
22 storage unit,
23 Second abnormality diagnosis section,
24 indicated value calculation section,
25 switching section,
30 braking / driving force control device,
32 storage unit,
33 Third abnormality diagnosis section,
34 Braking / driving force control unit,
100 Automatic steering system.

Claims (8)

A braking / driving force control device for controlling a braking / driving force distribution device for adding a yaw moment to the vehicle by controlling at least one of a braking force difference and a driving force difference between left and right wheels of the vehicle,
The vehicle includes a steering assist device that controls a steering device including an actuator that changes a rudder angle and performs automatic steering for causing the vehicle to travel along a target course shape.
The braking / driving force control device
An abnormality diagnosing unit for detecting the occurrence of a steering control abnormal state in which a steering angle changing operation of the vehicle based on the control of the steering assist device is impossible;
A braking / driving force control unit for adding a yaw moment to the vehicle so that the vehicle travels along the target course shape when the steering control abnormal state occurs during the automatic steering;
A braking / driving force control device comprising: A storage unit that stores a future course shape that is the target course shape from the present to a predetermined time later, and a state quantity that indicates a behavior of the vehicle detected by a state quantity detection device provided in the vehicle;
An estimated yaw rate calculated when the communication with the steering assist device is interrupted during the automatic steering and calculated based on the future course shape and the state quantity stored in the storage unit; The braking / driving force control device according to claim 1, wherein when the absolute value of the difference from the actual yaw rate is equal to or greater than a predetermined threshold, it is determined that the steering control abnormal state has occurred. When the communication with the steering assist device is interrupted and the steering control abnormal state occurs, the braking / driving force control unit is based on the future course shape and the state quantity stored in the storage unit. The braking / driving force control device according to claim 2, wherein a yaw moment is applied to the vehicle so that the vehicle travels along the target course shape.   The braking / driving force control device according to claim 2, further comprising a yaw rate sensor that detects an actual yaw rate of the vehicle. A steering control device for controlling a steering device including an actuator for changing a steering angle of the vehicle;
A braking / driving force control device for controlling a braking / driving force distribution device for adding a yaw moment to the vehicle by controlling at least one of a braking force difference and a driving force difference between left and right wheels of the vehicle;
A target course shape is calculated from at least one of the external environment information and map information of the vehicle, the steering control device is controlled based on the target course shape, and automatic steering is performed so that the vehicle travels along the target course shape. A steering assist device;
An automatic steering system comprising:
The braking / driving force control device includes an abnormality diagnosis unit that detects occurrence of a steering control abnormality state in which a steering angle change operation of the vehicle based on the control of the steering assist device is impossible, and the steering control during the automatic steering. An automatic steering system comprising: a braking / driving force control unit that applies a yaw moment to the vehicle so that the vehicle travels along the target course shape when an abnormal state occurs. The braking / driving force control device stores a future course shape that is the target course shape from a present time to a predetermined time later, and a state quantity indicating the behavior of the vehicle detected by a state quantity detection device provided in the vehicle. A storage unit
An estimated yaw rate calculated when the communication with the steering assist device is interrupted during the automatic steering and calculated based on the future course shape and the state quantity stored in the storage unit; 6. The automatic steering system according to claim 5, wherein when the absolute value of the difference from the actual yaw rate is equal to or greater than a predetermined threshold, it is determined that the steering control abnormal state has occurred. When the communication with the steering assist device is interrupted and the steering control abnormal state occurs, the braking / driving force control unit is based on the future course shape and the state quantity stored in the storage unit. The automatic steering system according to claim 6, wherein a yaw moment is added to the vehicle so that the vehicle travels along the target course shape.   8. The automatic steering system according to claim 6, wherein the braking / driving force control device includes a yaw rate sensor that detects an actual yaw rate of the vehicle.

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