Vehicle control system, vehicle control method, and non-transitory computer-readable storage medium storing program for executing the method

Abstract

The invention discloses a vehicle control system, a vehicle control method, and a non-transitory computer-readable storage medium storing a program for executing the method. The vehicle control system according to one aspect of the present invention may comprise: a brake device for braking a vehicle; a detector for detecting a failure of an electric power steering system of the vehicle; a steering sensor for detecting one or more pieces of steering operation information relating to a steering wheel operation of the vehicle; a first controller that receives the steering operation information to generate a target yaw rate when the detector detects the fault, and generates differential braking information including a left differential braking force or a right differential braking force required to track the target yaw rate; and a second controller receiving the differential braking information and controlling the braking device to generate the left side differential braking force or the right side differential braking force.

Description

Technical Field

[0001] The present invention relates to a vehicle control system, a vehicle control method and a non-transitory computer-readable storage medium storing a program for executing the method, and more specifically, to a vehicle control system, a vehicle control method and a non-transitory computer-readable storage medium storing a program for executing the method, which can alleviate the reduction in vehicle steering performance when a fault occurs in the vehicle's Electronic Power Steering (EPS) system and power assistance is difficult to perform. Background Art

[0002] In recent years, electronic vehicle chassis system products such as EPS (Electronic Power Steering) have become increasingly popular in the automotive industry. The EPS system assists the steering force acting between the rack and the pinion when operating the steering wheel by controlling the motor installed on the steering column or rack side, making steering easier for the driver.

[0003] However, as the life of the vehicle increases, the system performance decreases due to aging and fatigue of the electronic components, and the frequency of failures tends to increase. The output of the motor of the EPS system is not permanent, and as the vehicle ages, the motor output decreases. In addition, when driving frequently on high-load, rough roads such as unpaved roads, the output of the EPS system motor may decrease or fail at an early stage.

[0004] If the EPS system fails and loses power assistance, the driver can only rely on his own strength to bear the huge load generated between the ground and the vehicle's wheels when turning. As a result, the vehicle may deviate to one side or vibrate severely. On the other hand, if the EPS system fails and provides unnecessary assistance, it may cause a sharp turn when operating the steering wheel, making it difficult to drive normally. As mentioned above, EPS operation that does not match the driver's intention may cause serious problems to the safety of the vehicle while driving.

[0005] Therefore, it is necessary to develop a redundancy function in order to ensure minimum safety in the event of performance degradation and failure of components of the electronic vehicle chassis system such as the motor of the EPS system.

[0006] Patent document: Korean authorized patent No. 0468493 "Operation method of automobile electric power steering system", authorized on January 19, 2005. Summary of the invention

[0007] Problem that the invention aims to solve

[0008] The present invention aims to solve the problems mentioned above. The purpose of the present invention is to provide a vehicle control system, a vehicle control method and a non-temporary computer-readable storage medium storing a program for executing the method, which can alleviate the decline in the steering performance of the vehicle when the EPS system of the vehicle fails and loses power assistance for the driver's steering.

[0009] The problems of the present invention are not limited to the problems mentioned above, and a person skilled in the art will clearly understand other problems not mentioned through the following description.

[0010] Means used to solve problems

[0011] According to one aspect of the present invention, there is provided a vehicle control system, which alleviates the degradation of the vehicle's steering performance when a fault occurs in the vehicle's EPS (Electric Power Steering) system, and comprises: a braking device for braking the vehicle; a detector for detecting a fault in the EPS system; a steering sensor for detecting one or more steering operation information related to the steering wheel operation of the vehicle; a first controller, which receives the steering operation information to generate a target yaw rate when the detector detects the fault, and generates differential braking information including a left differential braking force or a right differential braking force required to track the target yaw rate; and a second controller, which receives the differential braking information and controls the braking device to generate the left differential braking force or the right differential braking force.

[0012] In a vehicle control system according to one aspect of the present invention, when the direction of the target yaw angular velocity is the direction in which the vehicle moves to the left, the differential braking information includes the left differential braking force; and when the direction of the target yaw angular velocity is the direction in which the vehicle moves to the right, the differential braking information may include the right differential braking force.

[0013] In the vehicle control system according to one aspect of the present invention, the steering operation information may include one or more of a rotation angle and a torque of the steering wheel.

[0014] In the vehicle control system according to one aspect of the present invention, the first controller may receive final steering state information of the vehicle as feedback and use the final steering state information as a correction factor when generating the differential braking information.

[0015] In the vehicle control system according to one aspect of the present invention, the first controller may receive disturbance information related to external effects occurring when the vehicle is traveling, and use the disturbance information as a correction factor when generating the differential braking information.

[0016] In a vehicle control system according to an aspect of the present invention, the interference information may include one or more of a friction force of a road on which the vehicle is traveling and a slope of the road.

[0017] In a vehicle control system according to one aspect of the present invention, the final steering state information and the interference information may be transmitted to the first controller via a CAN (Controller Area Network) of the vehicle.

[0018] According to one aspect of the present invention, the vehicle control system further includes: a rear-wheel steering device for steering the rear wheels of the vehicle, and the first controller can also generate rear-wheel steering information including the rear-wheel steering angle of the rear-wheel steering device required to track the target yaw angular velocity.

[0019] The vehicle control system according to one aspect of the present invention may further include: a third controller which receives the rear-wheel steering information and controls the rear-wheel steering device to generate the rear-wheel steering angle.

[0020] In a vehicle control system according to one aspect of the present invention, when the steering operation information meets the specified conditions, the first controller can set the left differential braking force and the right differential braking force to 0, and set the rear wheel steering angle to an angle opposite to the steering direction of the vehicle.

[0021] In the vehicle control system according to an aspect of the present invention, the steering operation information includes a rotation angle of the steering wheel, and the prescribed condition may be set to a case where the rotation angle is equal to or smaller than a prescribed angle.

[0022] In a vehicle control system according to one aspect of the present invention, when the steering operation information does not meet the specified conditions, the first controller may set the left differential braking force or the right differential braking force to a non-zero value, and set the rear wheel steering angle to an angle opposite to the steering direction of the vehicle.

[0023] According to another aspect of the present invention, a vehicle control method is provided, which alleviates the decline in the steering performance of the vehicle when the EPS (Electric Power Steering) system of the vehicle fails, and includes: a step of a detector detecting a failure of the EPS system; a step of a first controller receiving one or more steering operation information related to the steering wheel operation of the vehicle to generate a target yaw rate when the detector detects the failure; a step of the first controller generating differential braking information including a left differential braking force or a right differential braking force required to track the target yaw rate; and a step of the first controller transmitting the differential braking information to a second controller that controls a braking device for braking the vehicle.

[0024] In a vehicle control method according to one aspect of the present invention, when the direction of the target yaw angular velocity is the direction in which the vehicle moves to the left, the differential braking information includes the left differential braking force; and when the direction of the target yaw angular velocity is the direction in which the vehicle moves to the right, the differential braking information may include the right differential braking force.

[0025] According to one aspect of the vehicle control method of the present invention, the method may further include: a step in which the first controller generates rear-wheel steering information including a rear-wheel steering angle required to track the target yaw angular velocity; and a step in which the first controller transmits the rear-wheel steering information to a third controller for controlling a rear-wheel steering device for steering the rear wheels of the vehicle.

[0026] In a vehicle control method according to one aspect of the present invention, when the steering operation information meets the specified conditions, in the step of generating the differential braking information, the first controller sets the left differential braking force and the right differential braking force to 0, and in the step of generating the rear wheel steering information, the first controller can set the rear wheel steering angle to an angle opposite to the steering direction of the vehicle.

[0027] In the vehicle control method according to one aspect of the present invention, the steering operation information includes a rotation angle of the steering wheel, and the prescribed condition may be set to a case where the rotation angle is equal to or smaller than a prescribed angle.

[0028] In a vehicle control method according to one aspect of the present invention, when the steering operation information does not meet the specified conditions, in the step of generating the differential braking information, the first controller sets the left differential braking force or the right differential braking force to a non-zero value, and in the step of generating the rear-wheel steering information, the first controller may set the rear-wheel steering angle to an angle opposite to the steering direction of the vehicle.

[0029] In a vehicle control method according to one aspect of the present invention, in the step of generating the differential braking information, the first controller generates the differential braking information by using the final steering state information of the vehicle and the interference information related to the external action occurring during the driving of the vehicle as correction factors, and in the step of generating the rear-wheel steering information, the first controller may use the final steering state information and the interference information as correction factors to generate the rear-wheel steering information.

[0030] In the vehicle control method according to one aspect of the present invention, the interference information may include one or more of a friction force of a road and a slope of a road.

[0031] According to still another aspect of the present invention, there is provided a non-transitory computer-readable storage medium storing a program including at least one instruction for executing the vehicle control method according to one aspect of the present invention.

[0032] Effects of the Invention

[0033] According to the above configuration, a vehicle body control system, a control method of a vehicle body control system and a non-temporary computer-readable storage medium storing a program for executing the method according to one aspect of the present invention can alleviate the decline in vehicle steering performance through one or more of differential braking force and rear-wheel steering when the vehicle EPS system fails and loses power assistance to the driver's steering.

[0034] It should be understood that the effects of the present invention are not limited to the above-mentioned effects, and include all effects that can be inferred from the configuration of the invention described in the detailed description of the present invention or the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a diagram showing the configuration of a vehicle control system of one embodiment of the present invention.

[0036] Figure 2 is a diagram showing a detailed configuration of a first controller of a vehicle control system according to an embodiment of the present invention.

[0037] Figure 3 1 is a diagram showing a vehicle control operation performed by a vehicle control system according to an embodiment of the present invention when a prescribed condition is satisfied and the vehicle turns to the right.

[0038] Figure 4 1 is a diagram showing a vehicle control operation performed by a vehicle control system according to an embodiment of the present invention when a prescribed condition is satisfied and the vehicle turns to the left.

[0039] Figure 51 is a diagram showing a vehicle control operation performed by a vehicle control system according to an embodiment of the present invention when a prescribed condition is not satisfied and the vehicle turns to the right.

[0040] Figure 6 1 is a diagram showing a vehicle control operation performed by a vehicle control system according to an embodiment of the present invention when a prescribed condition is not satisfied and the vehicle turns to the left.

[0041] Figure 7 is a flow chart of a vehicle control method according to an embodiment of the present invention.

[0042] Figure 8 is a graph showing the steering torque of the steering wheel according to various vehicle control states in a J-turn steering motion.

[0043] Fig. 9 is a diagram showing a vehicle travel trajectory according to various vehicle control states in a J-turn steering motion.

[0044] Description of Reference Numerals

[0045] 100: Body control system

[0046] 110: Detector 120: Steering sensor

[0047] 130: Braking device 140: Rear wheel steering device

[0048] 150: first controller 160: second controller

[0049] 170: Third controller DETAILED DESCRIPTION

[0050] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. The present invention can be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted from the accompanying drawings, and the same reference numerals are assigned to the same or similar components throughout the specification.

[0051] The words and terms used in this specification and claims should not be interpreted as being limited to their usual or dictionary meanings, but in order to best explain one's invention, they should be interpreted as meanings and concepts corresponding to the technical ideas of the present invention in accordance with the principle that the inventor is able to define terms and concepts.

[0052] In this specification, the terms "including" or "having" are used to illustrate the existence of features, numbers, steps, actions, constituent elements, parts or their combinations recorded in the specification, rather than excluding the existence or additional possibilities of one or more other features, numbers, steps, actions, constituent elements, parts or their combinations in advance.

[0053] Figure 1 is a diagram showing the configuration of a vehicle control system of one embodiment of the present invention.

[0054] The EPS (Electric Power Steering) system 10 is provided in a vehicle to assist the steering force of the vehicle driver. When the vehicle driver operates the steering wheel, the EPS system 10 assists the steering force between the rack and the pinion of the steering mechanism by controlling the motor installed on the steering column or the rack side, thereby making the steering easier for the driver.

[0055] If the EPS system 10 fails, it cannot provide proper steering assistance when the driver operates the steering wheel, thereby making it difficult for the driver to perform the steering operation of the vehicle, and may cause serious safety problems.

[0056] In a vehicle control system 100 of an embodiment of the present invention, when the EPS (Electric Power Steering) system 10 of the vehicle fails and loses power assistance to the driver's steering, the decline in the vehicle's steering performance is alleviated. In a vehicle control system 100 of an embodiment of the present invention, when the EPS system 10 fails and cannot provide steering assistance, appropriate steering assistance can be provided to the driver's steering.

[0057] The vehicle control system 100 according to an embodiment of the present invention may be provided in the vehicle. Figure 1 A vehicle control system 100 according to an embodiment of the present invention may include a detector 110 , a steering sensor 120 , a braking device 130 , a rear-wheel steering device 140 , a first controller 150 , a second controller 160 , and a third controller 170 .

[0058] The detector 110 detects a malfunction of the EPS system 10. If the steering assist power cannot be provided to the driver due to the malfunction of the EPS system 10, the detector 110 may detect this and transmit the detection result to the first controller 150.

[0059] The EPS system 10 may include a motor for generating steering assist power, a control unit for controlling the motor, various components such as a rack for transmitting the steering assist power to wheels, and one or more sensors for detecting any one or more of the vehicle's speed, steering angle, and other factors.

[0060] If the motor of the EPS system 10 fails, the EPS system 10 may fail. For example, the brushes of the motor may be worn and unable to pass current normally, thereby reducing the output of the motor. In addition, the bearings of the motor may be worn and the rotor may not rotate normally.

[0061] If a control unit of the EPS system 10 fails, the EPS system 10 may also fail. The control unit interprets sensor data in the EPS system 10 and sends commands to the motor, and if it erroneously interprets sensor data or outputs abnormal motor control commands due to a failure, the EPS system 10 may fail.

[0062] The EPS system 10 may also fail if various components of the EPS system 10 fail. For example, if components such as the steering rack are damaged or fail to function properly due to impact, foreign matter, etc., the steering assist power provided by the motor may not be transmitted to the wheels of the vehicle.

[0063] If a sensor of the EPS system 10 fails, the EPS system 10 may also fail. If data on one or more of the vehicle speed, steering angle, and other factors cannot be collected normally due to a sensor failure, the control unit will not be able to output appropriate motor control commands. As a result, it is difficult for the EPS system 10 to operate normally.

[0064] The detector 110 can detect a fault occurring in a motor, a control unit, various components, a sensor, etc. of the EPS system 10. In this regard, the detector 110 may include one or more sensors, a detector controller, etc. At this time, the detector controller may be composed of a microcontroller unit (MCU) that processes one or more algorithms for detecting a fault in the EPS system 10.

[0065] The steering sensor 120 may detect one or more steering operation information related to the steering wheel operation of the vehicle. For example, the steering operation information may include one or more of the rotation angle of the steering wheel operated by the driver of the vehicle and the torque of the steering wheel. In other words, the steering sensor 120 may include one or more of a rotation angle sensor and a torque sensor.

[0066] The brake device 130 brakes the vehicle. In one embodiment of the present invention, the brake device 130 can suppress the rotation of each wheel of the vehicle. The brake device 130 can be hydraulic or electronic.

[0067] When the brake device 130 brakes only the left wheel of the vehicle, the left differential braking can be performed. In addition, when the brake device 130 brakes only the right wheel of the vehicle, the right differential braking can be performed.

[0068] When proper steering assist power cannot be provided to the driver due to a malfunction of the EPS system 10, steering assist power to the left can be obtained by performing left differential braking. When proper steering assist power cannot be provided to the driver due to a malfunction of the EPS system 10, steering assist power to the right can be obtained by performing right differential braking.

[0069] The rear wheel steering device 140 actively controls the rear wheel steering angle corresponding to the steering angle of the front wheels according to the driving condition of the vehicle. The rear wheel steering device 140 can reduce the turning radius of the vehicle by steering the rear wheels in the opposite direction (ie, in the reverse direction) to the steering direction of the front wheels.

[0070] On the other hand, when the vehicle is traveling at high speed, the rear wheel steering device 140 can also steer the rear wheels in the same direction as the front wheels (i.e., in the same direction). When the vehicle is traveling at high speed, if the rear wheel steering device steers the rear wheels in the same direction as the front wheels, the stability of the turning can be improved.

[0071] When the detector 110 detects a fault in the EPS system 10, the first controller 150 receives the steering operation information to generate a target yaw rate. The first controller 150 may be composed of a micro controller unit (MCU) for processing one or more algorithms.

[0072] When the detector 110 detects a fault of the EPS system 10, the fault detection information is transmitted to the first controller 150. In addition, the first controller 150 may receive one or more steering operation information related to the steering wheel operation of the vehicle from the steering sensor 120.

[0073] The first controller 150 generates differential braking information including a left differential braking force or a right differential braking force required to track the target yaw rate, and transmits the differential braking information to the second controller 160. The differential braking information can be used to generate differential braking through the brake device 130 of the vehicle.

[0074] When the first controller 150 generates differential braking information including a left differential braking force, and performs corresponding control, and generates a left differential braking force in the vehicle, a steering assist power to the left side can be provided to the vehicle. In addition, when the first controller 150 generates differential braking information including a right differential braking force, and performs corresponding control, and generates a right differential braking force in the vehicle, a steering assist power to the right side can be provided to the vehicle.

[0075] In other words, in one embodiment of the present invention, when the direction of the target yaw rate is the direction in which the vehicle moves to the left, the differential braking information may include the left differential braking force. In addition, when the direction of the target yaw rate is the direction in which the vehicle moves to the right, the differential braking information may include the right differential braking force.

[0076] On the other hand, the first controller 150 may generate rear wheel steering information including a rear wheel steering angle of the rear wheel steering device 140 required to track the target yaw rate. Specifically, the first controller 150 may set the rear wheel steering angle to an angle opposite to the steering direction of the vehicle.

[0077] The first controller 150 may transmit the rear wheel steering information to the third controller 170. The rear wheel steering information may be used for rear wheel steering of the rear wheel steering device 140.

[0078] In one embodiment of the present invention, the first controller 150 may apply the rear wheel steering information in priority to the differential braking information to compensate for the steering assist power lost due to a failure of the EPS system 10. This is because generating steering assist power through rear wheel steering is preferred in terms of efficiency or ride comfort compared to generating steering assist power through differential braking.

[0079] Next, the generation of the differential braking information and the rear wheel steering information by the first controller 150 will be described in more detail.

[0080] First, when the steering operation information meets a prescribed condition, the first controller 150 sets the left differential braking force and the right differential braking force to 0, and may set the rear wheel steering angle to an angle opposite to the steering direction of the vehicle.

[0081] The prescribed condition means a state in which the steering assist power loss can be compensated by the rear wheel steering alone. In this case, the rear wheel steering angle can be set to an angle opposite to the steering direction of the vehicle, thereby reducing the turning radius of the vehicle and assisting the steering.

[0082] As described above, the steering operation information may include the rotation angle of the steering wheel. In this case, the prescribed condition may be set to a case where the rotation angle is less than a prescribed angle. For example, the rotation angle may be selected between 15 degrees and 20 degrees.

[0083] Secondly, when the steering operation information does not meet the specified conditions, the first controller 150 sets the left differential braking force or the right differential braking force to a non-zero value, and can set the rear wheel steering angle to an angle opposite to the steering direction of the vehicle.

[0084] The predetermined condition may mean a state where the loss of steering assist power cannot be fully compensated by rear wheel steering alone. For example, when the rotation angle is set to be less than a predetermined angle, if the predetermined condition is not met, it means that the vehicle needs to turn relatively sharply.

[0085] In this case, it may be difficult to fully compensate for the loss of steering assist power due to the failure of the EPS system only by the rear wheel steering through the rear wheel steering device 140. At this time, the first controller 150 sets the left differential braking force or the right differential braking force to a non-zero value and sets the rear wheel steering angle to an angle opposite to the steering direction of the vehicle, so that the steering assist power can be compensated by the combination of rear wheel steering and differential braking even when turning relatively sharply.

[0086] As described above, when the EPS system 10 fails, the first controller 150 can comprehensively generate the differential braking information and the rear wheel steering information. As a result, the loss of steering auxiliary power due to the failure of the EPS system 10 can be effectively compensated by the combination of the differential braking of the vehicle's braking device 130 and the rear wheel steering of the rear wheel steering device 140.

[0087] If the vehicle is not provided with the rear wheel steering device 140, the first controller 150 may generate the differential braking information but not the rear wheel steering information. Thus, when the EPS system fails, the steering assist power loss may be compensated only by differential braking.

[0088] On the other hand, in one embodiment of the present invention, the first controller 150 may receive the final steering state information of the vehicle as feedback, and use the final steering state information as a correction factor when generating the differential braking information. In addition, the first controller 150 may receive the final steering state information of the vehicle as feedback, and use the final steering state information as a correction factor when generating the rear wheel steering information.

[0089] The first controller 150 may also receive interference information related to external effects occurring during the travel of the vehicle, and use the interference information as a correction factor when generating the differential braking information. In addition, the first controller 150 may also receive interference information related to external effects occurring during the travel of the vehicle, and use the interference information as a correction factor when generating the rear wheel steering information.

[0090] At this time, the interference information may include at least one of the friction of the road when the vehicle is traveling and the slope of the road.

[0091] In one embodiment of the present invention, the final steering state information and the interference information may be transmitted to the first controller 150 via a controller area network (CAN) of the vehicle.

[0092] Figure 2 is a diagram showing a detailed configuration of a first controller of a vehicle control system according to an embodiment of the present invention.

[0093] Reference Figure 2 , the first controller 150 of the vehicle control system 100 according to one embodiment of the present invention may include a first generator 151, a second generator 152, and a corrector 153. Among them, the first generator 151, the second generator 152, and the corrector 153 may not be physically separated configurations, but logically distinguished configurations in the MCU.

[0094] The first generator 151 receives one or more steering operation information related to the steering wheel operation of the vehicle to generate a target yaw rate. In one embodiment of the present invention, the first generator 151 may receive the steering operation information from the steering sensor 120 .

[0095] The second generator 152 generates differential braking information including the left differential braking force or the right differential braking force required to track the target yaw rate. In addition, the second generator 152 generates rear wheel steering information including the rear wheel steering angle of the rear wheel steering device 140 required to track the target yaw rate.

[0096] The differential braking information generated by the second generator 152 may be transmitted to the second controller 160. In addition, the rear wheel steering information generated by the second generator 152 may be transmitted to the third controller 170.

[0097] The second generator 152 may receive the final steering state information of the vehicle as feedback and use the final steering state information as a correction factor when generating the differential braking information. In addition, the second generator 152 may receive the final steering state information of the vehicle as feedback and use the final steering state information as a correction factor when generating the rear wheel steering information.

[0098] In other words, the second generator 152 may receive state-feedback and reflect the received state-feedback to generate the differential braking information and the rear wheel steering information.

[0099] At this time, the final steering state information may be transmitted to the second generator 152 via the controller area network 20 of the vehicle. In other words, the second generator 152 may communicate with the controller area network 20.

[0100] The corrector 153 may receive the interference information and correct the differential braking information or the rear-wheel steering information generated and output by the second generator 152 using the interference information.

[0101] At this time, the interference information may be transmitted to the corrector 153 via the CAN 20 of the vehicle. In other words, the corrector 153 may communicate with the CAN 20.

[0102] As described above, the interference information is related to the external effects occurring when the vehicle is traveling. For example, the interference information may include one or more of the friction of the road when the vehicle is traveling and the slope of the road.

[0103] The second controller 160 receives the differential braking information and controls the brake device 130 to generate the left differential braking force or the right differential braking force. For example, the second controller 160 may be composed of an ECU (Electronic Control Unit) for controlling the brake device 130.

[0104] A right differential braking force or a left differential braking force may be generated in the vehicle according to the control of the second controller 160, thereby compensating for the steering assist power loss of the EPS system. More specifically, when the right differential braking force is generated by the second controller 160, steering to the right may be assisted, and when the left differential braking force is generated by the second controller 160, steering to the left may be assisted.

[0105] The third controller 170 receives the rear wheel steering information and controls the rear wheel steering device 140 to generate the rear wheel steering angle. For example, the third controller 170 may be composed of an ECU (Electronic Control Unit) for controlling the rear wheel steering device 140.

[0106] The third controller 170 may receive the rear wheel steering information and control the rear wheel steering device 140 of the vehicle to generate a rear wheel steering angle opposite to the steering direction of the vehicle, thereby compensating for the loss of the EPS system steering auxiliary power.

[0107] Above, the configuration of the vehicle control system 100 according to one embodiment of the present invention is described in detail. Hereinafter, the operation of the vehicle control system 100 according to one embodiment of the present invention will be understood in detail.

[0108] Figure 3 1 is a diagram showing a vehicle control operation performed by a vehicle control system according to an embodiment of the present invention when a prescribed condition is satisfied and the vehicle turns to the right. Figure 4 1 is a diagram showing a vehicle control operation performed by a vehicle control system according to an embodiment of the present invention when a prescribed condition is satisfied and the vehicle turns to the left.

[0109] At this time, the predetermined condition may be that the rotation angle of the steering wheel is less than a predetermined angle. For example, the rotation angle may be selected between 15 degrees and 20 degrees.

[0110] exist Figure 3 and Figure 4 In the figure, the front left wheel W of vehicle V FL 、Front right wheel W FR 、Rear left wheel W RL and the rear right wheel W RR The state merely represents the control state of the vehicle control system 100 according to one embodiment of the present invention.

[0111] In other words, Figure 3 and Figure 4 In the figure, the front left wheel W of vehicle V FL and the front right wheel W FR The straight-ahead direction may be displayed, which may mean that even if the driver of the vehicle turns the steering wheel to the right or left as the EPS system 10 loses steering assist power, the wheels do not turn at all. It may also mean that the vehicle V does not show a state of turning to the right or left at a certain angle following the driver's steering operation.

[0112] Reference Figure 3 and Figure 4When the EPS system of vehicle V fails and loses steering assist power, and the steering operation information meets the specified conditions, the right differential braking force and the left differential braking force are set to 0, and the rear wheel steering angle can be set to an angle opposite to the steering direction of the vehicle.

[0113] More specifically, when the prescribed condition is met and the driver of the vehicle V turns to the right, the brake device 130 of the vehicle control system 100 does not generate a differential braking force, and the rear wheel steering device 140 causes the rear left wheel W to turn to the right. RL and the rear right wheel W RR Turn left ( Figure 3 ). As a result, the vehicle V can obtain steering assist power compensation to the right.

[0114] Furthermore, when the prescribed condition is met and the driver of the vehicle V turns to the left, the brake device 130 of the vehicle control system 100 does not generate a differential braking force, and the rear wheel steering device 140 causes the rear left wheel W to turn to the left. RL and the rear right wheel W RR Turn right ( Figure 4 ). As a result, the vehicle V can obtain steering assist power compensation to the left.

[0115] Figure 5 1 is a diagram showing a vehicle control operation performed by a vehicle control system according to an embodiment of the present invention when a prescribed condition is not satisfied and the vehicle turns to the right. Figure 6 1 is a diagram showing a vehicle control operation performed by a vehicle control system according to an embodiment of the present invention when a prescribed condition is not satisfied and the vehicle turns to the left.

[0116] exist Figure 5 and Figure 6 In the figure, the front left wheel W of vehicle V FL 、Front right wheel W FR 、Rear left wheel W RL and the rear right wheel W RR The state merely represents the control state of the vehicle control system 100 according to one embodiment of the present invention.

[0117] In other words, Figure 5 and Figure 6 In the figure, the front left wheel W of vehicle V FL and the front right wheel W FR The straight-ahead direction may be displayed, which may indicate that even if the driver of the vehicle turns the steering wheel to the right or left as the EPS system 10 loses steering assist power, the wheels do not turn at all. It may also indicate that the vehicle V does not show a state of turning to the right or left at a certain angle as the driver's steering operation is performed.

[0118] Reference Figure 5 and Figure 6 When the EPS system of vehicle V fails and loses steering assist power, and the steering operation information does not meet the specified conditions, the right differential braking force and the left differential braking force are set to non-zero values, and the rear wheel steering angle can be set to an angle opposite to the steering direction of the vehicle.

[0119] If the prescribed condition is not met, it means that the vehicle needs to turn relatively sharply. In this case, it may be difficult to fully compensate for the steering auxiliary power loss caused by the EPS system failure by only the rear wheel steering of the rear wheel steering device 140.

[0120] At this time, the vehicle control system 100 sets the left differential braking force or the right differential braking force to a non-zero value, and sets the rear wheel steering angle to an angle opposite to the steering direction of the vehicle, so that even when turning relatively sharply, a certain degree of steering assist force can be compensated by the combination of rear wheel steering and differential braking.

[0121] More specifically, when the prescribed condition is not satisfied and the driver of the vehicle V turns to the right, the braking device 130 of the vehicle control system 100 applies braking force to the front right wheel W and the front right wheel W, respectively. FR and the rear right wheel W RR The braking force B is generated on the right side to realize the right differential braking force, and the rear wheel steering device 140 makes the rear left wheel W RL and the rear right wheel W RR Turn left ( Figure 5 ). As a result, the vehicle V can receive steering assist power to the right side.

[0122] In addition, when the prescribed condition is not satisfied and the driver of the vehicle V turns to the left, the braking device 130 of the vehicle control system 100 applies the brakes to the front left wheel W and the front left wheel W, respectively. FL and the rear left wheel W RL The left differential braking force is realized by generating a braking force B, and the rear wheel steering device 140 causes the rear left wheel W to RL and the rear right wheel W RR Turn right ( Figure 6 ). As a result, the vehicle V can receive steering assist power to the left side.

[0123] Above, the configuration and operation of the vehicle control system 100 according to one embodiment of the present invention have been understood. Hereinafter, a vehicle control method according to one embodiment of the present invention will be understood.

[0124] Figure 7is a flow chart of a vehicle control method according to an embodiment of the present invention.

[0125] The vehicle control method S100 according to an embodiment of the present invention aims to alleviate the decline of the vehicle's steering performance when the EPS (Electric Power Steering) system of the vehicle fails. The vehicle control method S100 according to an embodiment of the present invention can be executed by a vehicle control system 100 according to an embodiment of the present invention.

[0126] Reference Figure 7 , the vehicle control method S100 according to one embodiment of the present invention may be performed as follows.

[0127] First, in step S110, the detector 110 detects a malfunction of the EPS system 10. If the steering assist power cannot be provided to the driver due to the malfunction of the EPS system 10, the detector 110 may detect this and transmit the detection result to the first controller 150.

[0128] Next, in step S120, the first controller 150 receives one or more steering operation information related to the steering wheel operation of the vehicle and generates a target yaw rate. The first controller 150 receives the detection result from the detector 110 and generates the target yaw rate according to the steering operation information. For example, the steering operation information may include one or more of the rotation angle of the steering wheel operated by the driver of the vehicle and the torque of the steering wheel.

[0129] Next, in step S130 , the first controller 150 generates differential braking information including a left differential braking force or a right differential braking force required to track the target yaw rate, and the differential braking information can be used to generate differential braking by controlling the braking device 130 .

[0130] If the direction of the target yaw rate is the direction in which the vehicle moves to the left, the differential braking information may include the left differential braking force. In addition, if the direction of the target yaw rate is the direction in which the vehicle moves to the right, the differential braking information may include the right differential braking force.

[0131] Next, in step S140, the first controller 150 generates rear wheel steering information including a rear wheel steering angle of the rear wheel steering device 140 required to track the target yaw rate. The first controller 150 may set the rear wheel steering angle to an angle opposite to the steering direction of the vehicle. The rear wheel steering information may be used to steer the rear wheels by controlling the rear wheel steering device 140.

[0132] The step S130 in which the first controller 150 generates the differential braking information and the step S140 in which the first controller 150 generates the rear wheel steering information can be performed simultaneously. In addition, any one of the steps S130 in which the first controller 150 generates the differential braking information and the step S140 in which the first controller 150 generates the rear wheel steering information can be performed first, and then the remaining step can be performed.

[0133] Next, in step S150 , the first controller 150 transmits the differential braking information to the second controller 160 . The differential braking information is received by the second controller 160 for controlling the braking device 130 .

[0134] The second controller 160 may receive the differential braking information and control the braking device 130 of the vehicle to generate the left differential braking force or the right differential braking force. When the right differential braking force is generated by the second controller 160, steering to the right may be assisted, and when the left differential braking force is generated by the second controller 160, steering to the left may be assisted.

[0135] Finally, in step S160, the first controller 150 transmits the rear-wheel steering information to the third controller 170. The rear-wheel steering information is received by the third controller 170 for controlling the rear-wheel steering device 140.

[0136] The third controller 170 may receive the rear wheel steering information and control the rear wheel steering device 140 to generate the rear wheel steering angle. The third controller 170 may receive the rear wheel steering information and control the rear wheel steering device 140 of the vehicle to generate a rear wheel steering angle that is opposite to the steering direction of the vehicle. By doing so, the steering assist power loss caused by the failure of the EPS system may be supplemented.

[0137] The step S150 in which the first controller 150 transmits the differential braking information to the second controller 160 and the step S160 in which the first controller 150 transmits the rear wheel steering information to the third controller 170 can be performed simultaneously. In addition, any one of the steps S150 in which the first controller 150 transmits the differential braking information to the second controller 160 and the step S160 in which the first controller 150 transmits the rear wheel steering information to the third controller 170 can be performed first, and then the remaining step can be performed.

[0138] On the other hand, when the steering operation information meets the specified conditions, in step S130 of generating the differential braking information, the first controller 150 sets the left differential braking force and the right differential braking force to 0, and in step S140 of generating the rear wheel steering information, the first controller 150 may set the rear wheel steering angle to an angle opposite to the steering direction of the vehicle.

[0139] The prescribed condition means that the steering assist power loss can be compensated by the rear wheel steering alone. In this case, when the rear wheel steering angle is set to an angle opposite to the steering direction of the vehicle, the turning radius of the vehicle can be reduced and the steering can be assisted.

[0140] As described above, the steering operation information includes the rotation angle of the steering wheel, and the prescribed condition may be set to a case where the rotation angle is equal to or smaller than a prescribed angle.

[0141] In addition, when the steering operation information does not meet the specified conditions, in step S130 of generating the differential braking information, the first controller 150 sets the left differential braking force or the right differential braking force to a non-zero value, and in step S140 of generating the rear-wheel steering information, the first controller 150 may set the rear-wheel steering angle to an angle opposite to the steering direction of the vehicle.

[0142] The predetermined condition may mean a state where the loss of steering assist power cannot be fully compensated by rear wheel steering alone. For example, when the rotation angle is set to be less than a predetermined angle, if the predetermined condition is not met, it means that the vehicle needs to turn relatively sharply.

[0143] In this case, it may be difficult to fully compensate for the steering assist power loss caused by the failure of the EPS system only by the rear wheel steering controlled by the rear wheel steering device 140. At this time, the first controller 150 sets the left differential braking force or the right differential braking force to a non-zero value and sets the rear wheel steering angle to an angle opposite to the steering direction of the vehicle, so that the steering assist power can be compensated to a certain extent by the combination of differential braking and rear wheel steering even when turning relatively sharply.

[0144] Furthermore, in the step S130 of generating the differential braking information, the first controller 150 may generate the differential braking information by using final steering state information of the vehicle and interference information related to external effects occurring during the travel of the vehicle as correction factors.

[0145] In addition, in the step S140 of generating the rear-wheel steering information, the first controller 150 may use the final steering state information and the interference information as correction factors to generate the rear-wheel steering information.

[0146] As described above, the interference information may include one or more of the friction of the road and the slope of the road.

[0147] On the other hand, the present invention further provides a non-transitory computer-readable storage medium storing a program for executing a vehicle control method according to an aspect of the present invention. Specifically, the present invention can provide a non-transitory computer-readable storage medium storing a program including at least one instruction for executing a vehicle control method according to an embodiment of the present invention.

[0148] At this time, the instructions may include not only machine codes generated by a compiler, but also high-level language codes executable by a computer.

[0149] The recording medium may include magnetic media (Magnetic Media) such as hard disks, floppy disks and magnetic tapes, optical recording media (Optical Media) such as Compact Disk Read Only Memory (CD-ROM) and Digital Video Disk (DVD), magneto-optical media (Magneto-Optical Media) such as floppy disks (Floptical Disk), hardware devices configured to store and execute program instructions such as ROM, RAM, flash memory, etc.

[0150] Figure 8 is a graph showing the steering torque of the steering wheel according to various vehicle control states in a J-turn steering motion.

[0151] Figure 8 The diagram shows the situation L1 in which the EPS system is normal, the situation L2 in which the EPS system fails and the differential braking control and rear wheel steering control according to the present invention are comprehensively implemented, the situation L3 in which the EPS system fails and only the differential braking control is implemented, and the situation L4 in which the EPS system fails and no compensation control is implemented.

[0152] Reference Figure 8 According to the present invention, it can be confirmed that it is possible to effectively compensate for the steering torque of the steering wheel that becomes heavier for the driver due to the loss of steering assist power caused by a failure of the EPS system.

[0153] Fig. 9is a diagram showing a vehicle travel trajectory according to various vehicle control states in a J-turn steering motion.

[0154] Fig. 9 The diagram shows the situation L1 in which the EPS system is normal, the situation L2 in which the EPS system fails and the differential braking control and rear wheel steering control according to the present invention are comprehensively implemented, the situation L3 in which the EPS system fails and only the differential braking control is implemented, and the situation L4 in which the EPS system fails and no compensation control is implemented.

[0155] Reference Fig. 9 , according to the present invention, it can be confirmed that even when the steering assist power is lost due to a malfunction of the EPS system, the total moving distance of the driving trajectory can be minimized to make the EPS close to a normal state.

[0156] As described above, when the performance of the EPS system is degraded or a failure occurs, the present invention can assist the driver's steering torque and maintain the steering performance of the vehicle by comprehensive control of differential braking (Steer by Brake, SbB) and rear wheel steering (Rear Wheel Steering, RWS). Therefore, according to the present invention, even if the EPS system fails, the decline in the steering performance of the vehicle can be alleviated, and serious safety problems can be prevented.

[0157] On the other hand, regarding the vehicle control system and method according to an embodiment of the present invention, the first controller 150, the second controller 160 and the third controller 170 can be implemented on more than one processor or ECU. In other words, the first controller 150, the second controller 160 and the third controller 170 are not necessarily separate chips physically separated from each other or implemented separately on processors.

[0158] Although the embodiments of the present invention have been described, the spirit of the present invention is not limited to the embodiments set forth in this specification, and those skilled in the art who understand the spirit of the present invention can easily propose other embodiments within the scope of the same spirit by adding, changing, deleting, adding, etc. to the constituent elements. However, this will also be considered to fall within the spirit of the present invention.

Claims

1. A vehicle control system, characterized in that: include: Braking device, brakes the vehicle, A detector is used to detect a fault of the electric power steering system of the vehicle. a steering sensor for detecting one or more steering operation information related to the steering wheel operation of the vehicle, a first controller that, when the detector detects the fault, receives the steering operation information to generate a target yaw rate, and generates differential braking information including a left differential braking force or a right differential braking force required to track the target yaw rate, and The second controller receives the differential braking information and controls the braking device to generate the left differential braking force or the right differential braking force.

2. The vehicle control system according to claim 1, characterized in that: When the direction of the target yaw rate is the direction in which the vehicle moves to the left, the differential braking information includes the left differential braking force; when the direction of the target yaw rate is the direction in which the vehicle moves to the right, the differential braking information includes the right differential braking force.

3. The vehicle control system according to claim 1, characterized in that: The steering operation information includes at least one of a rotation angle and a torque of the steering wheel.

4. The vehicle control system according to claim 1, characterized in that: The first controller receives final steering state information of the vehicle as feedback and uses the final steering state information as a correction factor when generating the differential braking information.

5. The vehicle control system according to claim 4, characterized in that: The first controller receives disturbance information related to external effects occurring during travel of the vehicle, and uses the disturbance information as a correction factor when generating the differential braking information.

6. The vehicle control method according to claim 5, characterized in that: The interference information includes at least one of friction of a road on which the vehicle is traveling and a slope of the road.

7. The vehicle control method according to claim 6, characterized in that: The final steering state information and the interference information are transmitted to the first controller via a controller area network of the vehicle.

8. The vehicle control system according to claim 1, characterized in that: Also includes: A rear wheel steering device for steering the rear wheels of the vehicle; The first controller also generates rear-wheel steering information including a rear-wheel steering angle of the rear-wheel steering device required to track the target yaw rate.

9. The vehicle control method according to claim 8, characterized in that: Also includes: The third controller receives the rear wheel steering information and controls the rear wheel steering device to generate the rear wheel steering angle.

10. The vehicle control method according to claim 8, characterized in that: When the steering operation information satisfies a prescribed condition, the first controller sets the left differential braking force and the right differential braking force to 0, and sets the rear wheel steering angle to an angle opposite to a steering direction of the vehicle.

11. The vehicle control method according to claim 10, characterized in that: The steering operation information includes a rotation angle of the steering wheel, and the predetermined condition is set to a case where the rotation angle is smaller than a predetermined angle.

12. The vehicle control method according to claim 10, characterized in that: When the steering operation information does not satisfy the prescribed condition, the first controller sets the left differential braking force or the right differential braking force to a non-zero value and sets the rear wheel steering angle to an angle opposite to the steering direction of the vehicle.

13. A vehicle control method, characterized in that: include: The steps of the detector to detect the fault of the electric power steering system of the vehicle, When the detector detects the fault, a first controller receives one or more steering operation information related to the steering wheel operation of the vehicle to generate a target yaw rate, The first controller generates differential braking information including a left differential braking force or a right differential braking force required to track the target yaw rate, and The first controller transmits the differential braking information to a second controller that controls a braking device for braking the vehicle.

14. The vehicle control method according to claim 13, characterized in that: When the direction of the target yaw rate is the direction in which the vehicle moves to the left, the differential braking information includes the left differential braking force; when the direction of the target yaw rate is the direction in which the vehicle moves to the right, the differential braking information includes the right differential braking force.

15. The vehicle control method according to claim 13, characterized in that: Also includes: the first controller generating rear wheel steering information including a rear wheel steering angle required for tracking the target yaw rate, and The first controller transmits the rear-wheel steering information to a third controller for controlling a rear-wheel steering device for steering rear wheels of the vehicle.

16. The vehicle control method according to claim 15, characterized in that: When the steering operation information meets the specified conditions, in the step of generating the differential braking information, the first controller sets the left differential braking force and the right differential braking force to 0, and in the step of generating the rear wheel steering information, the first controller sets the rear wheel steering angle to an angle opposite to the steering direction of the vehicle.

17. The vehicle control method according to claim 16, characterized in that: The steering operation information includes a rotation angle of the steering wheel, and the predetermined condition is set to a case where the rotation angle is equal to or smaller than a predetermined angle.

18. The vehicle control method according to claim 16, characterized in that: When the steering operation information does not meet the specified conditions, in the step of generating the differential braking information, the first controller sets the left differential braking force or the right differential braking force to a non-zero value, and in the step of generating the rear wheel steering information, the first controller sets the rear wheel steering angle to an angle opposite to the steering direction of the vehicle.

19. The vehicle control method according to claim 16, characterized in that: In the step of generating the differential braking information, the first controller uses the final steering state information of the vehicle and the interference information related to the external effects occurring during the driving of the vehicle as correction factors to generate the differential braking information, and in the step of generating the rear-wheel steering information, the first controller uses the final steering state information and the interference information as correction factors to generate the rear-wheel steering information.

20. A non-transitory computer-readable storage medium, characterized in that A program including at least one instruction for executing the vehicle control method according to claim 13 is stored.

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